1. Field of the Invention
The present invention is directed to the field of alternative fuels, and is more particularly directed to a method and system for storing and generating hydrogen. The method and system may be utilized to store a stable hydrogen source in a safe manner and to generate hydrogen gas therefrom upon demand for use as a fuel. In a preferred embodiment, the system and method are utilized on-board a vehicle to provide hydrogen as a primary or supplemental fuel source.
2. Description of Related Art
Hydrogen is a promising source of fuel for powering vehicles in conjunction with polymer electrolyte membrane (PEM) fuel cells and/or modified hydrogen internal combustion engines (ICE). Considerable efforts have been made to develop suitable storage technologies for storing the hydrogen fuel source onboard. A variety of factors must be considered in developing an acceptable hydrogen storage system for use onboard a vehicle. First and foremost is safety. It is important to develop a system for storing the hydrogen in a relatively stable and protected manner so as reduce safety concerns in the event of a collision.
Another consideration is overall economic viability and efficiency. A viable solution needs to provide a relatively lightweight system taking up little space or volume, yet providing significant fuel to enable the vehicle to operate for extended periods of time before re-fueling. In addition, it is important that the power needed onboard to generate the hydrogen be significantly less than the power produced by the fuel cell or engine for operating the vehicle. The cost of the system including the cost of any raw materials used to store and generate the hydrogen, as well as the cost of recycling or disposing of any waste products, must also be considered in assessing the overall economic viability of the system.
In addition, the environmental impact of the system is of critical importance. There is a desire to develop a system that minimizes pollution in terms of emissions and waste products generated in the production of raw materials and through operation of the vehicle. In this regard, there is a desire to minimize the use of fossil fuels in conjunction with the system to reduce carbon monoxide emissions and to reduce dependency on fossil fuel sources.
Lastly, the system must present an alternative for drivers that are relatively convenient for use, including providing a relatively convenient means for refueling or recharging the system and for disposing of any waste products.
The Department of Energy (“DOE”) has established goals for the development of hydrogen fuel systems to be used onboard vehicles. These goals address many of the considerations stated above including the amount of weight and volume utilized by the system in relation to the amount of energy supplied, as well as the cost of the fuel. A variety of different technologies is currently in various stages of development in an effort to meet these goals. While many of these technologies have promise, a need remains in the art for an innovative system that is relatively safe, efficient, cost effective, convenient, and environmentally friendly.